Need system for managing and storing configuration

We've got some of these pieces, but not in a form that a user can work with.

The need is some feature that will:
-Take parameters (engine, command-line, Moxi)
-Apply them cluster-wide (if desired...also single-node)
-Optionally persist them for restart
-Allow resetting values to defaults
-Display for the user what values have been changed, what the defaults are, etc